Liquid metal (LM) droplets made from gallium-based alloys exhibit excellent biomimetic locomotion and deformation capabilities under external stimulating fields and have presented potentials in a variety of applications. However, its application in robotics is presently hampered by limited maneuverability in two-dimensional (2D) space and weak cargo carrying capacity. Here, we propose a composite liquid metal droplet robot (LMDR) which appears as a LM droplet but exhibits an extraordinary actuating performance in 3D space. The LMDR is fabricated by assembling a hollow and spherical-shaped magnetic internal framework (IF) into a LM droplet, and the IF can be disassembled from the LM droplet with the application of an external magnetic field. The maneuver of the LMDR is realized using the interplay of electric and magnetic fields, and complex actuation especially jumping to avoid obstacles, climbing steep slopes, and rotating its body to the desired posture can be achieved. The hollow IF within the LMDR has a cargo carrying capacity and we demonstrate a proof-of-concept experiment to show the transportation and controlled release of a chemical indicator using the LMDR. More importantly, an in vitro targeted drug delivery and therapy trial to treat breast cancer cells (4T1) with a drug loaded LMDR is also successfully performed. The demonstrated capabilities of the LMDR present a promising potential in developing future targeted drug delivery and soft robotic systems with high controllability and multi-functionalities.

由镓基合金制成的液态金属（LM）液滴在外部刺激场下具有出色的仿生运动和变形能力，并在各种应用中都具有潜力。但是，目前它在机器人技术中的应用受到二维（2D）空间有限的机动性和较弱的货物承载能​​力的阻碍。在这里，我们提出了一种复合液态金属液滴机器人（LMDR），它看起来像LM液滴，但在3D空间中表现出非凡的驱动性能。LMDR是通过将空心的球形磁性内部框架（IF）组装到LM液滴中而制成的，并且可以通过施加外部磁场将IF从LM液滴中分解出来。LMDR的操纵是通过电场和磁场的相互作用来实现的，可以实现复杂的驱动，尤其是跳跃以避开障碍物，攀登陡坡以及将其身体旋转到所需姿势。LMDR中的中空IF具有载货能力，我们演示了概念验证实验来显示使用LMDR进行化学指示剂的运输和控制释放。更重要的是用载药的LMDR治疗乳腺癌细胞（4T1）的体外靶向药物递送和治疗试验也成功进行。LMDR展示的功能为开发具有高度可控性和多功能性的未来目标药物输送和软机器人系统提供了广阔的潜力。